Zeolite is used as a catalyst, a catalyst carrier, an adsorbent, and the like. In addition, a zeolite membrane-disposed article where a membrane is formed on a surface of a porous substrate made of metal or ceramic is used as a gas separation membrane and a pervaporation membrane by using a molecular sieve function of zeolite.
There are any kinds of zeolite such as LTA, MFI, MOR, AFI, FER, FAU, and DDR depending on the crystal structure. Of these, DDR (Deca-Dodecasil 3R) type zeolite is a crystal having silica as the main component, and it is known that the pore is formed by a polyhedron containing an oxygen eight-membered ring and that the oxygen eight-membered ring has a pore size of 4.4×3.6 angstrom (see W. M. Meier, D. H. Olson, Ch. Baerlocher, Atlas of zeolite structure types, Elsevier (1996)).
The DDR-type zeolite has a relatively small pore size among zeolite and has the possibility that it can be used as a molecular sieve for low molecular gas such as carbon dioxide (CO2), methane (CH4), and ethane (C2H6).
As a process of the production of DDR-type zeolite, there is disclosed a production process capable of producing a dense DDR-type zeolite membrane for a short period of time by specifying the content rate of 1-adamantanamine, silica, water, and ethylenediamine in the raw material solution (see, e.g., Patent Document 1). This process exhibits an excellent effect of being capable of producing a dense DDR-type zeolite membrane in a short period of time.